Knee joint



May 30,V 1959 LG, ARoN 2,509,586

KNEE .JOINT Filed Nov. 13, 1946 M5931 fw 24 L11/anion LoLgLlS 6. Caron Patented May 30, 1950 UNITED STATES PATENT OFFICE KNEE JOINT Louis G. Caron, Washington, D. C.

Application November 13, 1946, Serial No. 709,512

4 Claims.

This invention relates to improvements in knee joints for artificial limbs, of the character used to connect together the thigh and shin sections of such limbs.

The thigh and shin sections are usually pivoted together for relative swinging movement. This has required ordinarily the use of some latching means for securing the members in longitudinal alignment, such as was set forth in my prior patent for Artificial limb, No. 2,393,142, granted J anuary l5, 1946.

A control latch operated from the shoulder strap or waist-band strap may be considered objectionable not only because of the additional complexity and expense involved, but also because of the noise incident to the operation thereof, even when constructed in the simple and practical manner set forth in my prior patent.

One object of this invention is to improve the control between the thigh and shin sections, to maintain the alignment therebetween without the necessity for such a latch, and yet to measure proper articulation between the sections of the limb.

A further object of the invention is to improve the connection between the thigh and shin sections, to eliminate wear on the knee bolt provided therebetween, and yet provide a practical and effective connection between these sections.

These objects may be accomplished preferably by eliminating the latch which locks the sections together and substituting therefor a frictional connection with a lost motion connection between the sections that will allow engagement of the frictional connection whenever weight is applied to the limb. Thereby the pressure of weight applied to the limb locks the parts together through the frictional connection and thus eliminates the latch that has been required heretofore, producing a simple and less expensive construction.

The knee bolt preferably is attached to one section, such as the shin section, and has a yieldable connection with the other which provides a lost motion connection therebetween. This is provided preferably by means of a yieldable mounting for the knee bolt on the thigh section which will form a pivotal connection between the sections while yet allowing relative longitudinal movement therebetween.

'Ihe invention is illustrated in different embodiments in the accompanying drawings in which:

Fig. 1 is a vertical sectional view through the knee joint showing one form of the invention applied thereto;

Fig. 2 is a transverse sectional view therethrough;

Fig. 3 is a view similar to Fig. l, but showing a modied form of hinged connection;

Fig. 4 is a detail sectional view on the line 4-4 of Fig. 2; and

Fig. 5 is a similar view showing a modified form of knee bolt mounting.

This invention is adapted to be applied to thigh and shin sections of the usual character which are pivotally connected together by means of a knee joint, as in the form of an articial limb. These members usually are shaped to correspond substantially with the portions of a natural leg, and are formed of various materials suitable for the purpose, such as metal, wood, leather, plywood or the like.

The thigh section is designated generally by the numeral I and is articulated to a shin section 2, which forms the lower leg member of an articial leg. These members may be formed in any suitable or well-known manner, and usually are hollow, as illustrated generally in the drawings.

The shin section 2 is provided with an apron at the upper end thereof having ears 3 that embrace the lower end portion of the thigh section I, which lower end portion has a knee ball designated generally at 4, and is rounded or shaped to telescope into the apron at the upper end portion of the shin section 2, while permitting relative swinging movement or articulation of these parts. The ears 3 are connected together by a knee bolt 5 that extends therebetween through the knee ball 4 of the thigh section I. The knee bolt may be of any suitable or desired construction, although this is formed usually of a sleeve or bolt member secured by screw fastenings to lthe ears 3, which holds the knee bolt fixed to the ears, and inasmuch as the bolt extends through opposite sides of the knee ball fl of the thigh section I, these sections are pivotally connected together by means of the knee bolt for relative swinging motions with respect to each other.

This portion 4 of the thigh section I is provided with an opening 6, that extends transversely therethrough from side-to-side and through which the knee bolt 5 extends. This opening may be so fashioned as to form a journal for the lower portion of the bolt 5 to permit the latter to turn relative to the thigh section I, during articulation of these parts. This opening E has an enlarged upper portion of greater width throughout than the diameter of the bolt 5, but the bolt L5 is held in place yieldably by yieldable mountings 1 that are interposed between the upper side of the opening 6 and the upper face of the bolt 5, normally confining the bolt in the bottom of the opening but allowing yielding action for vertical shifting of the bolt relative thereto when desired. 'This will allow the thigh section I to move vertically downward relative to the shin section 2 but holding it yieldably in its elevated position.

The transverse opening 6 is intersected by an upwardly extending opening 8 through which an eye bolt 9 extends. The eye bolt Il has an eye formed by a transverse sleeve Io that surrounds f the bolt 5, while the eye bolt 9 extends upwardly through a plate I I seated upon transverse ledges I2 at opposite sides of the recess 8. This eye bolt, therefore, confines the thigh section I against vertical separation from the shin section 2, while holding the parts yieldably interconnected.

The apron at the upper end portion of the shin section 2 has mounted therein a transverse bridge I3 which forms a bearing support in the shin section and is secured in place to the side walls of the shin section by suitable means, such as screws I4. The bridge I3 has an upstanding arm I5, shown as hook shaped, and extending through a cut-away portion I 6 formed by a recess in one face of the thigh section I, which recess is in open communication with the recess 3 therein. The upper end of the arm I5 is shown as attached to the usual strap I'I that extends to the waistband or Suspenders for manipulation of the leg members.

The upper face of the bridge I 3 is formed with an arcuate surface I8, the curvature of which is coaxial with the lower face of the knee ball portion 44 of the thigh section I and having a center` substantially at the axis of the knee bolt 5. This arcuate surface I3 is covered with a fricM tion lining I9 of a material to provide a friotional grip with the under surface of the closed lower end l of the thigh section I, and preferably is of suitable material for this purpose, such as brake lining material which has been found to be effective.

It will be evident that upon forward pulling movement being imparted to the strap Il', this will act through the arm I5 to move the knee joint forward, swinging the thigh section I and thereby carrying the shin section 2 in a forward direction. As soon as these parts are dropped substantially into longitudinal alignment and weight is applied by a person wearing the artificial limb, this weight will serve to move downward the thigh section I, relative to the shin section This will serve to move the parts relatively under the yielding action of the tension members l until the lower face of the thigh section I engages the friction lining I9. This frictional engagement will prevent further relative turning movement and hold these parts in their aligned relationship during the joint swinging action of the parts I and 2 in the movement of the body on the articial leg. This frictional connection is accomplished without the use of a latch, such as has been required heretofore and yet the parts are effectively locked together at any desired angle. The device is simple in construction and less expensive to manufacture than the latch connection, and is a material improvement in operation.

The yieldable supports 'I preferably are formed of blocks of soft rubber which will effectively grip the upper face of the knee bolt 5 and which blocks may be bonded to the knee portion in wellknown manner, if desired. The shape of these blocks may be varied as desired, either wedgeshaped as shown in Fig. 4, or circular in cross section as indicated at 1 in Fig. 5. In the latter instance, the knee bolt 5 is shown as positioned eccentrically thereof.

The swinging action of the thigh section I relative to the shin section 2 may be limited in one direction, in which the parts are in straight line alignment, .by a resilient or soft rubber bumper 20 mounted in the upstanding arm I5 and in position to engage a shoulder designated at 2| formed on the face of the knee ball 4 of the thigh section at the bottom of the recess I5.

A modified form of knee joint is shown in Fig. 3, in which the thigh section 3| and shin section 32 are connected together substantially in the manner described by means of a knee bolt E3.

interposed between the eye of the latter and the upper end portion of the arm 36 -is a .yieldable bearing member 39 shown as in the form of a washer that surrounds the shank of the eye bolt and is formed of soft rubber or other suitable material that will apply downward yielding action thereto.

The knee bolt 33 extends through slots in opposite sides of the shin section 32 or is free of positive connection therewith, so as to permit of relative vertical movement therebetween. Therefore, upon the application of lengthwise prese. sure to the thigh section 3l, downward movement of the knee bolt 33 therewith relative to the shin section 32 will be permitted by the action of the rubber cushion 39 sufciently to move the arcuate lower surface thereof into engagement with the friction surface 35. This frictional engagement will hold the parts substantially in alignment orin their relative positions when engaged, permite ting joint movement thereof and without the necessity for a latched connection.

The eye bolt 9 or 3S not only serves to pre` vent extreme separation'of the sections but it also be adjusted to vary the spacing between the sections when separated and thereby the tenu sion applied to the friction lining. A tightening of the eye bolt will vary the tension of the resilient members I or 39.

The construction is such that no wear will be caused on the resilient members or on the lining I9 or 35, because as soon as pressure is applied on the thigh section, the periphery or curved surface at the lower face of the thigh section will engage the friction lining, taking the full load off the knee pivot. The construction is very simple and inexpensive to manufacture and is free of mechanical difficulties in service.

While the invention has been illustrated and described in different embodiments, it is recognized that variations and changes may be made therein without departing from the invention, ex-

cept insofar as specified in the claims.

I claim:

1. A knee joint for an articial limb having bearing upon the pivot pin for bodily movement of the pivot pin relative to said section, means forming a ball and skirt connection between the leg sections, means extending transversely in the lower leg section in bridging relation between opposite sides thereof and of appreciably less width than the width of the lower leg section and having means thereon for frictional engagement with the ball, said upper leg section having a slot therein with an abutment face at one end of the slot adjacent the ball forming means, and an arm connected with the skirt forming means and extending into the slot in position to engage laterally the abutment on the upper leg section, and a knee member connected with said arm.

2. A knee joint for an artificial limb, having upper and lower leg sections, a transverse pivot `pin for connecting the leg sections together, yieldable means mounted on the upper leg section and bearing upon the pivot pin for bodily movement of said pivot pin relative to said upper leg section, said upper leg section having a ball portion on the lower end thereof and having a slot therein adjacent the ball portion with an abutment at one side of the slot, a bridge extending transversely in the lower leg section between opposite sides thereof and having a surface formed thereon in cooperative relation with the ball portion, said bridge being appreciably less than half the width of the lower leg section, said bridge surface having means thereon for frictional bearing engagement with the ball portion upon relative movement of the sections toward each other, an arm connected with the bridge and extending upwardly therefrom into the slot in position for engagement with the abutment.

3. A knee joint for an artificial limb, having upper and lower leg sections, a transverse pivot pin for connecting the leg sections together, yieldable means mounted on the upper leg section and bearing upon the pivot pin for bodily movement of said pivot pin relative to said upper leg section, said upper leg section having a ball portion on the lower end thereof and having la slot therein adjacent the ball portion with an abuttransversely in the lower leg section between opposite sides thereof and having a surface formed thereon in cooperative relation with the ball portion, said bridge being appreciably less than half the width of the lower leg section, said bridge surface having means thereon for frictional bearing engagement with the ball portion upon relative movement of the sections toward each other, an arm connected with the bridge and extending upwardly therefrom into the slot in position for engagement with the abutment, and a knee oontrol member connected ywith said arm.

4. A knee joint for an articial limb having upper and lower leg sections, a transverse pivot pin for connecting the leg sections together for rel atve swinging movement of the leg sections yabout the axis of said pivot pin, means forming a ball and skirt connection between the leg sections for engagement upon relative movement of the sections toward each other, blocks of yieldable material bearing upon the pivot pin only at one side thereof and extending throughout the major portion of the length thereof and forming a yieldable connection between the pivot `pin and the upper leg section, means for adjusting the tension of the yieldable blocks on the pivot pin, said adjusting means comprising an eye-bolt having a sleeve portion telescoped over the pivot pin between the blocks of yieldable material, and means connecting the opposite end portion of the eyebolt with the upper leg section.

LOUIS G. CARON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,247,673 Hanger et al Nov. 127, 1917 1,552,869 Nevin Sept. 8, 1925 2,400,032 Talbot May 7, 1946 FOREIGN PATENTS Number Country Date 134,185 Great Britain Oct. 30, 1919 

